CVE-2026-55833: Netty SPDY zlib header block continues decoded expansion after maxHeaderSize truncation
Netty SPDY header decoding continues inflating zlib-compressed header blocks after the raw header parser has already exceeded maxHeaderSize and marked the frame truncated. At commit b2d2137c4404af425bf9d5d601a62576f5c06925, a 12,253-byte compressed SPDY header block can declare and inflate a 12 MiB header-name field with maxHeaderSize=16, forcing compression-amplified decode and skip work in a reachable SpdyFrameCodec pipeline.
References
- github.com/advisories/GHSA-mvh2-crg5-v77c
- github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003b
- github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6
- github.com/netty/netty/releases/tag/netty-4.1.136.Final
- github.com/netty/netty/releases/tag/netty-4.2.16.Final
- github.com/netty/netty/security/advisories/GHSA-mvh2-crg5-v77c
- nvd.nist.gov/vuln/detail/CVE-2026-55833
Code Behaviors & Features
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